arm64/boot: Disable trapping of PMZR_EL0 writes to EL2grafted

__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.
PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in
HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host
traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The
kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU
driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a
write from EL0 reaches the trap and takes the host down without a panic
message.

Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already
does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9
bits.

Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9")
Cc: stable@vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 166 insertions, 0 deletions

diff --git a/include/media/cec-notifier.h b/include/media/cec-notifier.h
new file mode 100644
index 000000000..b1c839734
--- /dev/null
+++ b/include/media/cec-notifier.h
@@ -0,0 +1,166 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * cec-notifier.h - notify CEC drivers of physical address changes
+ *
+ * Copyright 2016 Russell King.
+ * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ */
+
+#ifndef LINUX_CEC_NOTIFIER_H
+#define LINUX_CEC_NOTIFIER_H
+
+#include <linux/err.h>
+#include <media/cec.h>
+
+struct device;
+struct edid;
+struct cec_adapter;
+struct cec_notifier;
+
+#if IS_REACHABLE(CONFIG_CEC_CORE) && IS_ENABLED(CONFIG_CEC_NOTIFIER)
+
+/**
+ * cec_notifier_conn_register - find or create a new cec_notifier for the given
+ * HDMI device and connector tuple.
+ * @hdmi_dev: HDMI device that sends the events.
+ * @port_name: the connector name from which the event occurs. May be NULL
+ * if there is always only one HDMI connector created by the HDMI device.
+ * @conn_info: the connector info from which the event occurs (may be NULL)
+ *
+ * If a notifier for device @dev and connector @port_name already exists, then
+ * increase the refcount and return that notifier.
+ *
+ * If it doesn't exist, then allocate a new notifier struct and return a
+ * pointer to that new struct.
+ *
+ * Return NULL if the memory could not be allocated.
+ */
+struct cec_notifier *
+cec_notifier_conn_register(struct device *hdmi_dev, const char *port_name,
+			   const struct cec_connector_info *conn_info);
+
+/**
+ * cec_notifier_conn_unregister - decrease refcount and delete when the
+ * refcount reaches 0.
+ * @n: notifier. If NULL, then this function does nothing.
+ */
+void cec_notifier_conn_unregister(struct cec_notifier *n);
+
+/**
+ * cec_notifier_cec_adap_register - find or create a new cec_notifier for the
+ * given device.
+ * @hdmi_dev: HDMI device that sends the events.
+ * @port_name: the connector name from which the event occurs. May be NULL
+ * if there is always only one HDMI connector created by the HDMI device.
+ * @adap: the cec adapter that registered this notifier.
+ *
+ * If a notifier for device @dev and connector @port_name already exists, then
+ * increase the refcount and return that notifier.
+ *
+ * If it doesn't exist, then allocate a new notifier struct and return a
+ * pointer to that new struct.
+ *
+ * Return NULL if the memory could not be allocated.
+ */
+struct cec_notifier *
+cec_notifier_cec_adap_register(struct device *hdmi_dev, const char *port_name,
+			       struct cec_adapter *adap);
+
+/**
+ * cec_notifier_cec_adap_unregister - decrease refcount and delete when the
+ * refcount reaches 0.
+ * @n: notifier. If NULL, then this function does nothing.
+ * @adap: the cec adapter that registered this notifier.
+ */
+void cec_notifier_cec_adap_unregister(struct cec_notifier *n,
+				      struct cec_adapter *adap);
+
+/**
+ * cec_notifier_set_phys_addr - set a new physical address.
+ * @n: the CEC notifier
+ * @pa: the CEC physical address
+ *
+ * Set a new CEC physical address.
+ * Does nothing if @n == NULL.
+ */
+void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa);
+
+/**
+ * cec_notifier_set_phys_addr_from_edid - set parse the PA from the EDID.
+ * @n: the CEC notifier
+ * @edid: the struct edid pointer
+ *
+ * Parses the EDID to obtain the new CEC physical address and set it.
+ * Does nothing if @n == NULL.
+ */
+void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
+					  const struct edid *edid);
+
+/**
+ * cec_notifier_parse_hdmi_phandle - find the hdmi device from "hdmi-phandle"
+ * @dev: the device with the "hdmi-phandle" device tree property
+ *
+ * Returns the device pointer referenced by the "hdmi-phandle" property.
+ * Note that the refcount of the returned device is not incremented.
+ * This device pointer is only used as a key value in the notifier
+ * list, but it is never accessed by the CEC driver.
+ */
+struct device *cec_notifier_parse_hdmi_phandle(struct device *dev);
+
+#else
+
+static inline struct cec_notifier *
+cec_notifier_conn_register(struct device *hdmi_dev, const char *port_name,
+			   const struct cec_connector_info *conn_info)
+{
+	/* A non-NULL pointer is expected on success */
+	return (struct cec_notifier *)0xdeadfeed;
+}
+
+static inline void cec_notifier_conn_unregister(struct cec_notifier *n)
+{
+}
+
+static inline struct cec_notifier *
+cec_notifier_cec_adap_register(struct device *hdmi_dev, const char *port_name,
+			       struct cec_adapter *adap)
+{
+	/* A non-NULL pointer is expected on success */
+	return (struct cec_notifier *)0xdeadfeed;
+}
+
+static inline void cec_notifier_cec_adap_unregister(struct cec_notifier *n,
+						    struct cec_adapter *adap)
+{
+}
+
+static inline void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
+{
+}
+
+static inline void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
+							const struct edid *edid)
+{
+}
+
+static inline struct device *cec_notifier_parse_hdmi_phandle(struct device *dev)
+{
+	return ERR_PTR(-ENODEV);
+}
+
+#endif
+
+/**
+ * cec_notifier_phys_addr_invalidate() - set the physical address to INVALID
+ *
+ * @n: the CEC notifier
+ *
+ * This is a simple helper function to invalidate the physical
+ * address. Does nothing if @n == NULL.
+ */
+static inline void cec_notifier_phys_addr_invalidate(struct cec_notifier *n)
+{
+	cec_notifier_set_phys_addr(n, CEC_PHYS_ADDR_INVALID);
+}
+
+#endif